Number bases

  • More Secret Transmissions
    problem

    More Secret Transmissions

    Age
    16 to 18
    Challenge level
    filled star filled star empty star
    In 'Secret Transmissions', Agent X could send four-digit codes error free. Can you devise an error-correcting system for codes with more than four digits?
  • Learn About Number Bases
    article

    Learn About Number Bases

    We are used to writing numbers in base ten, using 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. Eg. 75 means 7 tens and five units. This article explains how numbers can be written in any number base.
  • The Knapsack Problem and Public Key Cryptography
    article

    The Knapsack Problem and Public Key Cryptography

    An example of a simple Public Key code, called the Knapsack Code is described in this article, alongside some information on its origins. A knowledge of modular arithmetic is useful.
  • A Story About Absolutely Nothing
    article

    A Story About Absolutely Nothing

    This article for the young and old talks about the origins of our number system and the important role zero has to play in it.